node.js - NodeJS is swallowing my exception thrown from a callback -

assume following code:

mymodule.dostuff(options, function(err, results) {     if (err) console.log('e', err);     if (err) throw err;     console.log(results); }); 

the offending code is:

return new promise(function(resolve, reject) {     try {         throw new error('test error');         resolve('success');     } catch (ex) {         console.log('r', ex);         reject(ex);     } }); 

and farther chain:

self.adapter     .collect(self.options)     .then(function(data) {         self.callback(null, data);         if (self.runnable) {             settimeout(self.collect.bind(self), 2000);         }     }, function(error) {         self.callback(error);     }); 

the 'e [error info here]' statement prints, throw statement apparently ignored. app happily continues doing whatever else instructed , not crash expected. why?

i never found answer specific library using, after switching q library, exposed crucial step may have been missing before also. if there no reject handler @ top level of promise chain, exception may swallowed. according q documentation, way around call .done() @ top of chain flushes pending exceptions caller.